Space weathering by simulated micrometeorite bombardment on natural olivine and pyroxene: A coordinated IR and TEM study

Weber, I.; Stojic, Aleksandra N.; Morlok, A.; Reitze, Maximilian P.; Markus, Kathrin; Hiesinger, H.; Pavlov, S. G.; Wirth, Richard; Schreiber, Anja; Sohn, Martin; Hübers, Heinz‐Wilhelm; Helbert, J.

doi:10.1016/j.epsl.2019.115884

Cited by 35 publications

(41 citation statements)

References 44 publications

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“…2016; Weber et al. 2020). Those experiments have shown that the changes in slope, reflectance, and band depth are not linear with repeated laser pulses, with the change in spectral slope in the near‐infrared region from the first irradiation being much larger than changes due to subsequent irradiation steps, particularly for olivine (Sasaki et al.…”

Section: Discussionmentioning

confidence: 99%

“…Laboratory experiments exploring the effects of ion irradiation have demonstrated that olivine reddens and darkens more efficiently than pyroxene over time scales estimated to reflect 10 5 yr of space exposure in the asteroid belt (Marchi et al 2005). Pulse-laser irradiation experiments can simulate impact events, although they are often run for multiple irradiations, simulating up to hundreds of millions of years exposure (Corley et al 2016;Weber et al 2020). Those experiments have shown that the changes in slope, reflectance, and band depth are not linear with repeated laser pulses, with the change in spectral slope in the near-infrared region from the first irradiation being much larger than changes due to subsequent irradiation steps, particularly for olivine (Sasaki et al 2001(Sasaki et al , 2003.…”

Section: Space Weathering Of Itokawamentioning

confidence: 99%

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Comparison of space weathering features in three particles from Itokawa

Burgess

Stroud

Sandford

2021

Meteorit & Planetary Scien

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The return of samples from S-type asteroid 25143 Itokawa have enabled significant improvements in our understanding of space weathering on asteroids and the link between S-type asteroids and ordinary chondrites. We report on three new particles, providing details on space weathering of adjacent grains within a particle and several different phases. The features we observe are consistent with formation via irradiation from the solar wind, as opposed to micrometeoroid bombardment. We also see differences in the degree of weathering for grains collected from the two different touchdown locations on the asteroid. Continued analysis of new grains from Itokawa allow us to draw a more complete picture of the variety of space weathering features and the processes that lead to their formation on Itokawa and other airless bodies.

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Section: Discussionmentioning

confidence: 99%

Section: Space Weathering Of Itokawamentioning

confidence: 99%

Comparison of space weathering features in three particles from Itokawa

Burgess

Stroud

Sandford

2021

Meteorit & Planetary Scien

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“…The timescale of the energy delivery is comparable to the timescale of the laser pulse (≈100 fs) causing instant ablation of the irradiated volume. The ablated material is subsequently redeposited on top of the in situ damaged zone creating amorphous redeposition layer with possible presence of nanophase Fe particles (Weber et al 2020). Thus, the resulting pattern of the affected surface grains is expected to be more complex than in the case of ion irradiation.…”

Section: Wavelength-dependent Changes and Penetration Depthmentioning

confidence: 99%

Comparison of space weathering spectral changes induced by solar wind and micrometeoroid impacts using ion- and femtosecond-laser-irradiated olivine and pyroxene

Flanderová

Brunetto

Ďurech

et al. 2021

A&A

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Context. Space weathering is a process that changes the surface of airless planetary bodies. Prime space weathering agents are solar wind irradiation and micrometeoroid bombardment. These processes alter planetary reflectance spectra and often modify their compositional diagnostic features. Aims. In this work we focused on simulating and comparing the spectral changes caused by solar wind irradiation and by micrometeoroid bombardment to gain a better understanding of these individual space weathering processes. Methods. We used olivine and pyroxene pellets as proxies for planetary materials. To simulate solar wind irradiation we used hydrogen, helium, and argon ions with energies from 5 to 40 keV and fluences of up to 1018 particles cm−2. To simulate micrometeoroid bombardment we used individual femtosecond laser pulses. We analysed the corresponding evolution of different spectral parameters, which we determined by applying the Modified Gaussian Model, and we also conducted principal component analysis. Results. The original mineralogy of the surface influences the spectral evolution more than the weathering agent, as seen from the diverse evolution of the spectral slope of olivine and pyroxene upon irradiation. The spectral slope changes seen in olivine are consistent with observations of A-type asteroids, while the moderate to no slope changes observed in pyroxene are consistent with asteroid (4) Vesta. We also observed some differences in the spectral effects induced by the two weathering agents. Ions simulating solar wind have a smaller influence on longer wavelengths of the spectra than laser irradiation simulating micrometeoroid impacts. This is most likely due to the different penetration depths of ions and laser pulses. Our results suggest that in some instances it might be possible to distinguish between the contributions of the two agents on a weathered surface.

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“…The interpretation that the TF reflects the plagioclase component is consistent with the previously discussed mechanical stability of the various minerals in a rock. Therefore, the pyroxene component in the linear mixture is probably over‐estimated because of its stability (Moroz et al., 2014; Weber et al., 2020). The non‐fitting peak arising from the pyroxene component is probably an artifact of the availability of a pyroxene spectrum, which correctly matches the characteristics of the pyroxenes present at Mercury in terms of chemical composition and crystallographic properties (Putnis, 1992).…”

Section: Discussionmentioning

confidence: 99%

“…Investigations of the plagioclases from the Lappajärvi crater, Finland, revealed an almost highest possible degree of disorder, showing a complex interaction of shock and the impact melt (Bischoff & Stöffler, 1984). Simulated micrometeorite bombardment with laser irradiation of powder pressed pellets leads to a decrease of spectral contrast of the Reststrahlen bands (RBs) of plagioclase feldspar samples and a formation of smaller grain sizes due to a gardening process, which disturbs the flat surface of the pellets (Moroz et al., 2014; Weber et al., 2020).…”

Section: Introductionmentioning

confidence: 99%